Retrospective Study Demonstrating Earlier Diagnosis of Colorectal Cancer in African Americans Compared to Caucasians after IBD Diagnosis in VA Patients

Zhang HC, Panara A, Thrift A, El-Serag H, Hou J, Waljee AK. Retrospective Study Demonstrating Earlier Diagnosis of Colorectal Cancer in African Americans Compared to Caucasians after IBD Diagnosis in VA Patients. Poster session presented at: Digestive Disease Week Annual Conference; 2016 May 22; San Diego, CA.

Related HSR&D Project(s)

• CDA 11-217 – Risk Stratification and Targeted Therapy for HELP Diseases in Veterans

DDW Character Limit: 2900 Category: AGA Title: Retrospective Study Demonstrating Earlier Diagnosis of Colorectal Cancer in African Americans Compared to Caucasians after IBD Diagnosis in VA Patients Hao Chi Zhang, Ami Panara, et al. Aaron Thrift, Hashem El-Serag, Jason Hou Background: Patients with inflammatory bowel disease (IBD) are at an increased risk of colorectal cancer (CRC) compared to the general population. Other factors, such as family history, primary sclerosing cholangitis, IBD duration, and IBD extent have been previously reported to confer additional CRC risk. In the general population, African American race has been associated with an increased risk of CRC as well as occurrence of CRC at a younger age compared to caucasian race. The aim of this study was to assess the association of race on CRC among patients with IBD. Methods: We performed a retrospective cohort study of patients with IBD and CRC in the national VA datasets. Patients with IBD and CRC were identified by ICD-9 codes; IBD and CRC diagnoses were then confirmed by manual chart review. Demographic, IBD, and CRC characteristics were abstracted by chart review using a standardized abstraction form. Patients with CRC diagnosed outside of the VA, incomplete cancer staging data, or CRC diagnosed prior to IBD were excluded from analyses. Associations of race and IBD and CRC characteristics were analyzed using Fisher's Exact test, chi-square, t-test, and univariate and multivariate logistic regression. Results: A total of 153 patients (11 African-American and 142 Caucasian patients) met inclusion criteria and were included in analyses. The mean age of IBD diagnosis was 46 years for African Americans and 43 for Caucasians (p = 0.57). The proportions of patients with ulcerative colitis (UC) were similar in both African Americans and Caucasians (72% vs. 71%, respectively). There were no significant differences in UC or Crohn's disease (CD) extent based on race. There were 6 cases of primary sclerosing cholangitis among Caucasians, but no cases among African Americans. IBD duration prior to CRC was significantly shorter among African Americans [11.15 years (SD 9.21)] compared to Caucasians [22.16 years (SD 15.04), p = 0.018]. This difference remained significant after adjusting for both IBD type and gender (p = 0.023). When stratified by IBD type, the difference in time to CRC diagnosis by race was no longer statistically significant among UC patients (p = 0.0985), but approached significance among CD patients (p = 0.051). Conclusions: In a national retrospective cohort of IBD patients with CRC, we observed African Americans with IBD are diagnosed with CRC earlier after IBD diagnosis than Caucasians, specifically patients with CD. The IBD characteristics between African American and Caucasian IBD patients were otherwise similar, including age at IBD diagnosis, proportion of UC, and IBD extent. This observation suggests African American patients with IBD, particularly Crohn's disease, may require more aggressive and earlier surveillance for CRC.